THE NATURAL-HISTORY OF PATIENTS WITH CLAUDICATION WITH TOE PRESSURES OF 40 MM HG OR LESS

Purpose: This study was performed to determine the natural history of patients with symptoms of claudication and systolic toe pressures (TP) of 40 mm Hg or less. Methods. We followed the clinical course of 56 m en with stable claudication and TP of 40 mm Hg or less. All TP measure ments were performed on at least two occasions 6 months apart. Primary end points included development of rest pain, tissue loss, or gangren e. The clinical course of 56 case controls with TP greater than 40 mm Hg matched for age, sex, and race was used for comparison. Results: Du ring a mean (+/- SD) follow-up time of 31 +/- 4 months, 37 (66%) patie nts with TP of 40 mm Hg or less remained stable, and 19 (34%) had ulce ration (n = 10), rest pain (n = 6), or gangrene (n = 3). Nine (24%) of the 37 stable patients had gradual improvement of TP values greater t han 40 mm Hg. Among the 19 patients whose conditions deteriorated, eig ht (42%) patients underwent successful bypasses, and five (26%) patien ts required amputations. Two patients who had rest pain had spontaneou s resolution, and three patients who had ulcerations heated without in tervention. In contrast, five (9%) of the case controls with TP greate r than 40 mm Hg had rest pain (n = 2) or gangrene (n = 3) (p = 0.003). Among patients with TP of 40 mm Hg or less, there were no statistical ly significant differences between the stable patients and patients wi th deteriorating conditions in age, ankle-brachial indexes, or risk fa ctors (including diabetes mellitus). However, diabetes conferred a hig her probability of clinical deterioration CP = 0.005, Kaplan-Meier). C onclusions: In patients with symptoms of intermittent claudication, TP of 40 mm Hg or less portends clinical deterioration. Patients with di abetes in this group have a significantly higher risk of development o f critical ischemia. Close scrutiny is warranted.